Shock-absorber for rotary drilling kellys



Feb. 26, 1952 B. BRONZAN SHOCK-ABSORBER FOR ROTARY DRILLING KELLYS Filed March 1, 1949 25 BY ATTORN Patented Feb. 26, 1952 SHOCK-ABSORBER. FOR ROTARY DRILLING KELLY Blasito Bronzan, Los Angelcs, Calii., assignor' to Baash-Ross Tool Company, Los Angeles, Calif a corporation of California Application March'l, 1949, Serial No. 78,899

12 Claims.

This invention relates to means for protectin a drilling kelly-against undesirable impact with the bushing normally held in a rotary table and to provide an adequate load-bearing surface for contact with-the bushing when the kelly is being supported therefrom.

During normal rotary drilling operations the upper part of the drill stem is provided with a griefstem or kelly which extends through the Kelly bushing held within a socket of the rotary table. The kelly ordinarily includes a longitudinally extending. drive portion of polygonal section fitting within the. Kelly drive bushing, rotation of the table being transmitted by the bushing to the kelly and thereby to the drill stem. The ends of the kelly are normally provided with joints or enlarged connection portions, the upper end being ordinarily provided with a box connection (internally threaded to receive the pin connection of the swivel), whereas the lower end of a kelly is ordinarily provided with a pin engagement for mating engagement with the box of the drill stem disposed below the kelly. These end portions of a kelly are generally enlarged with respect to the drive portion of. the kelly and are often referred to as the,

upset portions of the kelly. Moreover, in many instances, the upper upset of the kelly is pro.

a kelly. In some forms of Kelly bars the elevator: space. or circumferential recess is separatedfrom, the main drive portion of the kelly by a stop shoulder;

In all instances, however, the drive portion of the kelly merges by a curved or radiused area into an enlarged upper portion, whether such enlarged upper portion includes elevator space or not. Since the Kelly bushing of the rotary table fits, the polygonal cross section of the kelly rather: closely, the relatively sharp corner edges of the drive bushing may deliver a sharp blow tow-the curved base of the upset in the event the kelly is rapidly lowered through the bushing to. During drilling operations, the

rest. thereon. kelly; together with the bushing is repeatedly inserted into a rat hole casing, the entire weight of thekelly and swivel being supported on the. bushing while: the latter rests on the top of the: rat hole. Probably the weakest part of a kelly is. the: curved zone between the upset and the polygonal drivev portion, and impact delivered to contact defined by the edges of the bushing, and

undesirable wedg ingof the kelly in the drive? bushing sometimes occurs.

The present invention is" particularly directed to means for protecting a kelly from damage due to impact or high stress applied to the upper upset. The invention'provide's anadeduate hearing area beween the upper upset of the kelly and the Kelly bushing. By the means of this invention the kelly (and depending string of drill pipe and tools) can be'safely supported upon an adequate bearing surface when the kelly lowered into extreme position throughthe rotary table, or when the kelly and the Kelly bushing are supported in a rat" hole. The present invention provides an attachment which can be used on standard, presently existing kellys without changes therein or in the customary Kelly bushings, and also contemplates, a modified kelly provided with such attachment. Generally stated, the invention contemplates a housing adapted to extend from an upper upset zoneofa kelly to a lower zone in the drive portion of a kelly, the lower" portion of said housing enci'r-'- cling the drive portion and including a bottom; face of apreciable area. This bottom face may be fiat or it may be of a configuration mating that of the top of the bushing; The housing contains resilient means arranged to yieldably resist upward movement of. the housing along! the kelly. The housing, together"with its resilient means, thereby forms a' shock absorber preventing. the kellyfrom dangerous impact with a Kelly bushing and also provides an adequate bearing surface adapted to support the kelly upon the bushing of the rotary table, thereby preventing'a' dangerous localization and application of forces to thatportion of the lielly'where the upper upset diameter blendswith the drive portion of the kelly.

An-object of the present invention, therefore, is to disclose and provide means for'protectingla kelly from undesirable shocks. and impact.-

A further. object of the invention is to. disclose and provide a means arranged. for attachmentto A still further object of the. invention is to disclose and provide a housing: capablepf being removably attached to theupper part of a. kelly for limited longitudinal movement thereon, said housing including resilient means arranged to yieldably resist upward movement of the housing along said kelly.

These and other objects, advantages, and adaptations of the invention will become apparent to those skilled in the art from the following description of certain illustrative forms in which the invention may be embodied, said illustrative forms being illustrated on the appended drawings, wherein:

Fig. 1 is a side elevation, partly diagrammatic, illustrating the relationship between a kelly and a rotary table of the character normally used in the rotary drilling of oil, water, and gas wells.

Fig. 2 is an enlarged side elevation, partly in section, of one form of device.

Fig. 3 is a transverse view taken along the broken plane III-III in Fig. 2.

Fig. 4 is an enlarged side elevation, partly in section, of a modified form of device.

As generally illustrated in Fig. 1, a kelly provided with a drive portion I of polygonal cross section extends through the rotary table 5 supported on suitable ball or cone roller bearings and driven from a pinion shaft 6 by a suitable drive means, not shown.

The rotary table includes a socket containing the Kelly drive bushing i. The drive bushing en gages the polygonal cross section drive-portion I0 of the kelly, thereby transmitting torque and rotation to the kelly and depending sections of drill pipe, tools, etc. 7

Each end of the kelly is provided with an enlarged upset portion or enlarged connection end.

Normally, the upper upset II is provided with a 3 box connection, whereas the lower upset I2 is provided with a pin connection. Although forms of kellys vary, the preferred and customary form includes a stop shoulder l3 of substantially the same diameter as the upper upset II, the stop shoulder merging with the polygonal drive portion 10 by means of a curved or filleted zone 14. Between the stop shoulder l3 and the enlarged connection end I i, there is provided a circumferential recess I5 delineated by opposing faces [5 and 11; this recess accommodating the upper end of the device of this invention, not shown in Fig. l, but shown in Figs. 2-4.

The drive portion of the kelly may be either.

square, hexagonal, or octagonal, the customary square type being illustrated in the drawings. It is to be understoodthat the kelly is provided with a through bore .I8 through which circulation is maintained during drilling operations.

During drilling, the kelly is rotated and slowly lowered, but in some instances the kelly is permitted to descend rapidly and forcible contact ensues between the relatively sharp edges of they bushing 1 and the upper upset II, and particularly between such relatively sharp edges and the filleted zone l4 of the kelly. Failures of a kelly have occurred by reason of such impact and even though failure does not occur, the kelly has, in many instances, been notched and.damaged and difiiculty has been encountered in withdrawing the kelly and removing the bushing. The device of the present invention arrests and ameliorates the effects of undesired shock or impact and provides a wide surface for contact with the upper end of the Kell drive bushing or other portion of the rotary table. I

As best shown in Figs. 2 and 3, the device of the present invention may have a longitudinally 's plit housing comprising the housing portions and 20, these housing portions being bolted or otherwise suitably connected together as by means of bolts 2 I. The lower end of said housing extends to a zone around the drive portion I0 of the kelly and includes the inwardly extending flange 22 encircling the drive portion l0 and conforming to the cross sectional shape of such drive portion for slidable movement therealong. The upper end of the housing overlies the circumferential recess I5 and is provided with a lip or inwardly extending flange 23 which encircles this portion of the kelly. The internal diameter of the housing is suificient to slidably receive the stop shoulder 13, thereby providing a chamber 24 between the housing and the drive portion of the kelly. Means are provided within this chamber for yieldably urging the housing downwardly and for resisting upward movement of the housing along the kelly.

In a normal, 6 in. square kelly the chamber 24 is, in effect, four interconnected chambers having a maximum depth of about in. each. Although any resi1ient,- elastic means may be contained in the chamber 24 or, each of the portions thereof, it has been found desirable to position within these chambers longitudinally extending strips of corrugated rubber or rubber composition, one of said strips being indicated at 25. A single moulded rubber sleeve, splitlongitudinally to facilitate placement around the kelly, may be used instead of separate strip elements indicated at 25. It will be noted that the ends of the rubber bear against the lower face of the stop shoulder I5 and against the inwardly extending flange 22 of the housing, thereby yieldably urging the housing downwardly so that in its normal position the upper flange or lip 23 of the housing rests against the face I! of the stop shoulder 13.

In the event the kelly is lowered into forcible contact with the Kelly bushing, it will be noted that the outer face 26 of the flange 22 (being of relatively large area) will contact with the Kelly bushing, further downward movement of the kelly compressing the rubber 25 in the chamber 24 and dampening the shock of the impact. The

housing will move upwardly and the longitudinal length of the recess I5 may be so regulated that the upper face of the flange or lip 23 may contact face 16 of such recess as the resilient material 25 is substantially completely collapsed, thereby causing some of the load to be carried through the resilient material 25 and some part, if not all, of the load to be carried from the upset or flipper connection end II through the "face I6 and housing portions 20 and 20. The lower face 26 of the housing may be of a contour complementary to the top surface of the Kelly bushmg.

It will be noted that there is no possibility of notching or denting the curved portion I4 of the kelly and no localized stresses are imparted thereto even when the kelly is negligently handled, thereby expediting drilling operations without sacrificing safety. It may also be noted that when the rubber is compressed under load, such load is absorbed (in part) by the housing. Fig. 4 illustrates a, somewhat modified form of device, the housing in this instance consisting of a tubular member 30 provided at its upper end with a split gland 3| extending into and slidable upon the surface of the recess l5 and maintained in locked position not only by the threaded connection 32 but also by lock screws such as 33.

The lower end of the housing 30 is also provided with a split gland 34 encircling thedrive section of the kelly, the gland 34 being similarly held in position as by means of threads 35 and lock screws 36. The chamber Within the housing is substantially filled with corrugated, preformed or folded rubber 25 in a manner similar to that described heretofore in connection with the device illustrated in Figs. 2 and 3. It will also be noted that the lower gland is provided with a relatively large, flat impact face 26. The operation of this modified form is substantially identi- 2' vided with. another recess for use as an elevator space, such elevator space and the recess 15 being preferably (but not necessarily) separated by a stop shoulder or stop ring carried by or formed in the upper upset. stood, moreover, that although reference has been made to a 6 in. kelly (for purpose of illustration), the invention is not limited thereto,

It is to be undersince it is applicable to kellys of various sizes and configurations.

All changes and modifications coming within the scope of the appended claims are embraced thereby.

I claim:

1. Means for protecting a kelly provided with a drive portion of polygonal section, an enlarged connection end, a stop shoulder adjacent the end of the drive portion, and a circumferential recess between said shoulder and enlarged connection end, comprising: a housing adapted to extend from a zone in the circumferential recess to a zone in the drive portion of said kelly, said housing being slidably movable longitudinally of the kelly in the region of the stop shoulder; bottom means carried by the lower portion of the housing a and adapted to slidably encircle the drive portion of the kelly; means carried by the upper portion of the housing extending into and arranged to encircle the circumferential recess of the kelly; and elastic, resilient, compressible means carried within the housing, and adapted to extend between a stop shoulder of the kelly and the bottom means of the housing.

2. Means of the character stated in claim 1 wherein the housing is separable to facilitate attachment thereof to the kelly.

, 3. Means of the character stated in claim 1 wherein th resilient and compressible means comprise rubber composition formed with corrugations transverse to the axis of the housing and kelly to which the housing is applied.

4. Means of the character stated in claim 1 wherein the bottom of the housing is provided with a face adapted to contact a Kelly bushing.

5. Means of the character stated in claim 1 wherein the bottom of the housing is provided with a face having a configuration virtually mating the top of a Kelly bushing.

6. Means of the character stated in claim 1 wherein the housing is separable to facilitate attachment thereof to the kelly and the resilient and compressible means comprise a longitudinally split rubber composition sleeve.

'7. A kelly provided with a shock absorbing device, said kelly including a drive portion of polygonal section and an enlarged upper connection end, comprising: a circumferential recess formed in the enlarged upper end of the kelly; a stop shoulder between said recess and the drive portion of the kelly; a housing encircling the kelly and having an upper inwardly flanged end extending into the recess and a bottom inwardly flanged end encircling the drive portion; and a resilient, compressible means within the housing and bearing against the stop shoulder and the bottom inwardly extending flange.

8. A kelly of the character stated in claim 7, wherein the longitudinal length of the recess is correlated to the length of the housing and the compressible means whereby the upper inwardly flanged end of the housing will traverse the recess when the compresssible means is fully compressed.

9. A kelly of the character stated in claim 7, wherein the housing is composed of separable portions and the compressible means comprise a longitudinally split, transversely corrugated rubber composition sleeve.

10. A kelly of the character stated in claim 7 wherein the housing is composed of separable portions and the bottom, inwardly flanged end is in sliding, non-rotatable contact with the drive portion.

11. Means for protecting a kelly provided with a drive portion of polygonal section, an enlarged connection end, a reduced portion between said end and drive portion and a stop shoulder between said reduced portion and drive portion, compris-.

ing: a housing provided with inwardly-extending upper and lower flanges, said housing being arranged to straddle said stop shoulder of the kelly, the lower flange cooperating with the drive portion of the kelly to prevent relative rotation between the housing and kelly, and resilient means within the housing arranged to yieldably resist upward movement of the housing along the kelly and toward the connection end.

12. A kelly having a drive portion of polygonal section, an enlarged connection end, a reduced portion between said end and drive portion, a stop shoulder between said reduced portion and drive portion and a removably attachable impact sleeve nonrotatably connected by said kelly and extending 'over the stop shoulder, said impact sleeve being longitudinally slidable over a limited portion of the kelly, said impact sleeve including resilient means arranged to yieldably resist movement of said sleeve longitudinally toward the connection end.

BLASITO BRONZAN.

REFERENCES CITED The following references are of record in the flle of this patent:

UNITED STATES PATENTS Number Name Date 373,440 Chapman Nov. 22, 1887 1,501,994 Greve July 22, 1924 1,686,945 Abercrombie Oct. 9, 1928 2,147,436 Grandfleld Feb. 14, 1939 2,170,057 Kerr Aug. 22, 1939 2,212,153 Eaton et al. Aug. 20, 1940 2,424,492 Morris July 22, 1947 2,504,393 Cook Apr. 18, 1950 

